Unit Five - Weathering and Erosion - Glaciers Flashcards
What is a glacier?
A mass of ice and snow that moves downhill under the force of gravity.
How does a glacier move? (3)
- Snow and Ice accumulates
- The glacier moves downhill under its own mass and gravity
- Acts like a fluid and flows in motion (Called “River of Ice”)
What is a Continental Glacier?
- Huge sheets of ice
- Covers entire land masses
What is a Valley Glacier? (2)
- Form in high elevations
- In mountain valleys
What are U - Shaped Valleys & V - Shaped Valleys?
- U - Shaped = Glacial Erosion (Lateral)
- V - Shape = Water Erosion (Vertical)
What are Erratics? (4)
- An identifiable glacial feature
- Large DEPOSITED fragments
- Transported from a glacier
- Doesn’t fit with rest of the environment
Ex: A boulder of sandstone is picked up by a glacier, transported, and deposited on top of a limestone bedrock
What are Drumlins? (5)
An identifiable glacial feature
- An elongated hill
- A mound of unsorted sediments
- It is formed when there is a resistant rock, forcing the glacier to drive over it, then it smoothes the rock, creating the “tail end”
- Aligned in the direction of ice flow
- Where the “tail end” is pointing, that is where the glacier moved.
What are Eskers?
- Identifiable Glacial Feature
- Long winding ridge
- Made up of sands and gravel
- Remnant of the melting of an under glacier
What are Terminal Moraines? (4)
- An identifiable glacial feature
- A deposited mound of till that is pushed
- Along the leading edge of a glacier
- Sediment is unsorted
It is basically unsorted sediments that are pushed from the leading edge of a glacier, and that glacier later recedes, keeping the pushed sediments in the same place
What are glacial grooves? (3)
- An Identifiable Glacial Feature
- Long parallel scratches
- Formed by sediment embedded in a glacier
What is a Kettle Lake? (5)
An Identifiable Glacial Feature.
- A piece of ice falls from a glacier
- It gets partially buried and sediment surrounds it
- The ice melts
- This creates a depression in the ground
- Water line increases, creating a lake
What is an outwash plain?
An Identifiable Glacial Feature
When running water that melted from a retreating glacier sorts sediments in the outwash plain.